A 52-year-old man comes to the office with a 2-week history of shortness of breath and dry cough. The patient has noticed decreased exercise tolerance that limits his daily activities. A Doppler probe placed at the cardiac apex reveals the following blood flow pattern across the patient's mitral valve. The point marked by the arrow would best correspond to which of the following auscultation findings?

Question

A 52-year-old man comes to the office with a 2-week history of shortness of breath and dry cough.  The patient has noticed decreased exercise tolerance that limits his daily activities.  A Doppler probe placed at the cardiac apex reveals the following blood flow pattern across the patient's mitral valve.  The point marked by the arrow would best correspond to which of the following auscultation findings?

Quizplus · Accepted Answer

11ec160b_3c99_8ce5_9249_efe12c92fca6_MD0001_00 The graph shows the normal pattern of blood flow across the mitral valve from the left atrium to left ventricle during diastole. There is an initial phase of rapid transmitral blood flow after the mitral valve opens, which represents early passive ventricular filling (E wave). This is followed by a period of minimal blood flow (diastasis), which occurs due to equalization in pressure between the left atrium and ventricle. Finally, there is a second peak corresponding to increased transmitral blood flow due to atrial contraction (A wave). The A wave ends with the first heart sound (S1) caused by mitral (and tricuspid) valve closure. When present, a third heart sound (S3) occurs during diastole and is best heard with the bell of the stethoscope over the cardiac apex with the patient in the left lateral decubitus position. It is due to sudden limitation of ventricular movement during passive ventricular filling. An S3 may be a normal finding in healthy young adults; however, in patients age >40 it suggests abnormal ventricular cavity enlargement (ie, eccentric hypertrophy). An S3 is often associated with chronic severe mitral regurgitation, chronic aortic regurgitation, or dilated cardiomyopathy; occasionally, it may be present in high cardiac output states such as pregnancy or thyrotoxicosis. (Choice A) A fourth heart sound is a low-frequency, late diastolic sound coinciding with atrial systole. It is caused by a sudden rise in end-diastolic pressure as blood strikes a stiff left ventricular wall, and most commonly suggests concentric left ventricular hypertrophy such as occurs in prolonged hypertension or severe aortic stenosis. (Choice B) A midsystolic click is associated with mitral valve prolapse. In patients with mitral valve prolapse and mitral regurgitation, there will be blood flow away from an apical Doppler probe during systole. (Choice C) The second heart sound results from closure of the semilunar valves (aortic and pulmonic) at the end of systole. Educational objective: A third heart sound (S3) occurs due to sudden limitation of ventricular movement during passive ventricular filling in diastole. An S3 in patients age >40 suggests abnormal ventricular cavity enlargement such as occurs in chronic severe mitral regurgitation, chronic aortic regurgitation, or dilated cardiomyopathy.

A 52-Year-Old Man Comes to the Office with a 2-Week